Pulp-feed regulator.



I. l. WITHAM.

'PULP FEED REGULATOH.`

APPLICATION FILED APRA-1,1917.

mmm July 17, 1917.

3 SHEETS-SHEET l.

l. 1. WlTHAM.

PULP FEED REGULATOR.

APPLICATION FILED APR. I4, I9I-7. v l y Nl H3@ Patented July 17, 1917.

3 SHEETSSHEET 2.

HIIIIIIIIIIIIIIIIII Snom/Hoz @s i I@ Mmc wmf/@w PuLPFEEn' REGULATOR.

APPLICATION FILED APR-14| |91]- 3 -SHEETS-SHEET 3.

l WILT* Ifgiiiig mmm@ July 17, 1917.

To all whom t may concern.'

i han rara rATnT Ormea.

ISAAC JT. WITHA'M, 0F HUDSON FALLS, NEW YORK, VASSIGNOR 0F ONE-HALF T0 GEORGE S. WI'II-IAIVI, SR., 0F HUDSON FALLS, NEW YORK.

PULP-Farin REGULATOR.

readme.

Be it known that r,V im@ J. waant,

` a citizen of the United States, lresiding at Hudson Falls, inthe county of Washington and State of NewI York, have invented cer.-

tain new and useful Improvements in Pulpl lEeed Regulators, of which the following is a specification.

In the manufacture of paper, paper pulp, of which the paper is made, is fed inv a continuous stream to an endless belt which supports the pulp until it has become suthickness will result.

ciently firm to support itself on the drying rollers over which it is finally carried in the form of a continuous web to suitable reeling mechanism. It has been found, however, that it is impossible to maintain the pulp at a constant consistency or density, and if care is not taken to regulate the continuous flowof pulp onto the supportin belt according to its density, paperI o varying Although it is the usual custom to regulate the flow of `the pulp by manually operated valves, some attempts have vbeen made to automatically control the flow of the pulp by floats disposed intanks from which the pulp is fed, or to compensate for any variation in the density of the -pulp by correspondingly increasing or decreasing the speed at which the supporting belt is moved by means of feelers constantly in contact with the paper web which detect any variation in thickness therein, and which are electrically connected to the belt driving motor, to vary the speed ofthe motor according to the variations. linasmuch as the floats in the feed tank were operated 'not only by the density of the pulp, but also b the necessary surge and variation of liquid evel in the tank, and inasmuch as an actual variation had to result in the paper web already formed before the feeler could operate, it was impossible to construct an apparatus sensitive to the slightest variations of density and which would give accuracy and evenness to the finished paper.

The object of this invention is to provide means for automatlcally regulating the flow Specication of Letters Patent.v

' density of the ratentea .any 1r', mit..

Application med April 1/1, 1917. serial-11o, 161,985.

of the pulp, such means being responsive to the variation in the electric conductivity of the pulp due -to its varying density,

A further. object of the invention is to render vthe regulating means adjustable to insure the desired thickness of the paper.

A further object of the invention is to provide a simple device for determining the pulp in order to properly regulate its flow. V

ln carrying out the invention two pairs of electrodes, one in each line of a shunted elecL tric circuit, are'suspended in the pulp feed tank.` Each pair of electrodes is connected in series with a resistance, one of the .resist- `ances being preferably variable. Bridged across the shunted circuits, connecting the electrodes and the resistance 'in each circuit, is the field coil of a motor. l[ may also connect a galvanometer adapted to register in terms of density in parallel with the motor field. The motor whose eld is /bridged across the electrode circuits may operate a fly ball governor to yopen or close a valve controlling the pulp feed opening, according to the speed at which the motor is run.` When pulp is introduced into the feed tank an electric circuit flows across It will be understood that/li' do not limit L l myself to the express construction herein i set forth.

Referring to the drawings, Figure 1 is a somewhat diagrammatic view showing my invention applied to a pulp feeder.

Fig. 2 is a diagrammatic representation of the circuits employed in carrying out my invention.

lFig.. 3 is a detailed view showing a particular form of governor mechanism for operating the valve.

Fig. 4 shows my particular arrangement of circuits connected to a recording galva- .being introduced into the tank or being fed therefrom, in order to maintain the pressure at the feed opening al constant. To control the flow of the pulp through the feed opening a1 there is provided a valve B shown as a sliding gate mounted on a rock shaft b, pivoted in a suitable bearing C fixed to the floor of the tank. The opposite end of the rock shaft b is connected by means of a link b1 to a second rock shaft D pivoted) in a an upright rod F bearing E on the tank A. The other end of the rock shaft D is pivotally connected to passing through the bearing block G, the gear H, and the hollow shaft H carried by the gear H (Fig. 3). The upper end of the rod F is enlarged and has therein a circumferential groove into whichis loosely fitted an annular collar i pivotally connected to the lifting arms l of a fly-ball governor I by links 2. The'lifting arms 1 of the governor are pivoted on a rod 3 carried by the hollow shaft H and operate up and down in slots z. formed in the hollow shaft. The gear H ismounted in the bearing block G.

. The gear H is driven through suitable reducing gearing J by a shunt wound direct current motor K. In addition to the ordinary field coil K1 connected` in series with I' the usual resistance Kz (see Fig. 2) shunted across the brushes 7c, 7c, there is provided an auxiliary field coil L connected independently ofthe field K1 and adapted to increase or decrease the speed of the motor.

The motor is connected with any suitable source of direct current through lines O and P at 103 and 704.

Suspended in the pulp feed tank are two pairs of ,electrodes M and N. One of the electrodes M is connected at m to` wire P leading 'from a'source of direct current. The

other electrode M is connected in series with a resistance r in a suitable resistance box R with the other lwire O leading from a source of direct current at 0. One of the. electrodes N is connected to the wire O' at n. The other electrode N is connected in series with a resistance r1 `in the resistance box R to the wire P at p. In series also with the electrodes N, but shunted across the resistance r1 is avariable resistance or rheostat R by the variation of the resistance of which the current flowing through the circuit n, p may be regulated. Connected to the circuit mo at point s between M and 1 and to the circuit n, p at point t between N and 7- and R isa `bridge circuit leading through the auxiliary field L of the motor K. This arrangement forms the Well known Wheatstone bridge circuit, having for its four arms the circuits mp s, mp t, on, s, and on t, and having for its shunt circuit the auxiliary field coil circuit s t (see Fig. 2). I may also connect a recording galvanometer U adapted to register in terms of density in parallel with the auxiliary field circuit at points u and u.

In operation, pulp of normal consistency is first introduced into the tank A. The resistance of the rheostat R is then adjusted lso that no current fiows across the bridge circuit. The motor K is thenstarted. It is run at a speed suitable to cause the fly-ball gov- `ernor I to open the valve or gate B sufficiently to feed the proper amount of pulp of normal thickness. If there is any variation in the density of the pulp, its electric conductivity is varied accordingly, and more or less current may flow across the electrodes M and N. This variation of current across the electrodes destroys the electrical balance of the bridge and causes a current to flow across they bridge. If the current fiows in one direction, the magnetic field of the coil L tends to strengthen the field of the usual field coil K, thereby increasing the speed of the motor and causing the ffy-balls to lift higher to open the valve. If the current passes through the field coil in the opposite direction the magnetic field produced by the auxiliary coil tends to neutralize the effect of the field K to retard the speed of the motor. Should it be desired to vary the thickness of the finished paper, the variable resistance R is moved to vary the speed of the motor and permit more or less pulp to pass through the feed opening a.

In Figs. 4.- and 5 I have shown the use of A the electrodes and a galvanometer to determine the density of the pulp, apart from the use of a motor to regulate the feed.

I claim as my invention:

l. In a pulp feed receptacle, electrodes within the receptacle, and a recording galvanometer inthe electrode circuit to determine the density of the pulp.

2. In a pulp feed regulator, a pulp receptacle having a feed opening, a valve for controlling said opening, and means for actu-` ating said valve comprising a motor having a source of current and an auxiliary field winding, and electrodes within the rece tacle and in circuit with the auxiliary eld, whereby the variations in density of the mames pulp will increase or decrease the field strength of the motor to open or close said valve.

3. lln a pulp feed regulator, a pulp receptacle having a feed opening, a valve for controlling said opening, an electric motor, electrodes Within the receptacle and in circuit Wth a field Winding of the motor, and

a governor mechanism for controlling said valve and itself regulated by the speed of lo the motor as the density and conductivity of the pulp varies.

n testimony whereof, ll have hereunto subscribed my name. A

' isaao J. vvrrnAM. 

